The present invention relates to a method for granulating a food, for instance, a raw material for food or a food composition such as curry (or curry roux), stew, soup, sauce, a variety of seasonings and a variety of spices.
Methods for granulating foods without using any water are disclosed in, for instance, Japanese Un-examined Patent Publication (hereunder referred to as "J.P. KOKAI") Nos. Sho 58-116652 and Sho 59-66848. More specifically, J.P. KOKAI No. Sho 58-116652 relates to a novel method for preparing oil and fat-containing granular seasonings which can be stored at ordinary temperature over a long period of time by substantial inhibition of the oxidation of the oil and fat present therein, which comprises the steps of mixing a heated liquid of solid oil and fat, which have an open-tubed melting point ranging from about 30.degree. to 45.degree. C., preferably about 35.degree. to 38.degree. C. and are heated into the molten state, with a mixed powdery seasoning which is preferably warmed, in advance, with stirring; cooling the resulting mixture down to a temperature of about 10.degree. to 15.degree. C. to thus solidify the oil and fat components and then granulating the solidified mixture by a means such as grinding or crushing. On the other hand, J. P. KOKAI No. Sho 59-66848 relates to a novel dry-granulation method which comprises mixing, in a powdery condition, a powdery material to be granulated with a powdery binder having an open-tubed melting point ranging from 40.degree. to 130.degree. C., then heating the resulting powdery mixture at a temperature of not less than the open-tubed melting point of the powdery binder and subsequently cooling the processed and heated mixture down to a temperature of not more than the open-tubed melting point of the binder.
However, the foregoing methods provide granular materials whose particle size distribution is wider than that observed on granules prepared by granulation through extrusion and the methods may often require a process for adjusting the particle size of the resulting granular products. Moreover, the granules prepared by these methods are weakly associated as compared with those prepared by granulation through extrusion and thus the granules are easily destroyed even by an accidental weak external shock.
On the other hand, a method for granulating foods through extrusion is a kind of wet-method as disclosed in, for instance, Japanese Examined Patent Publication (hereunder referred to as "J.P. KOKOKU") No. Sho 53-45380. The method of this type comprises water addition-granulation-hot air drying processes, can provide granules having a narrow particle size distribution and does not require any process for adjusting particle size. However, the method requires water-addition and drying processes and this results in poor operating efficiency. Moreover, the drying process leads to disappearance of desired smells of foods and deteriorates the taste thereof.